1. Learning Objectives
The structure of proteins and their possible jobs (including enzymes)in our cells
How and Where Transcription and Translation occur.
How DNA, mRNA, tRNA, rRNA all work together to go from Gene Protein

2. A Brief Review:
Monomer
Polymer
Amino Acids
Proteins

4. A chain of amino acids (monomers) is called a protein (polymer)
Peptide Bonds
Protein
-but proteins fold in on themselves…
….to make a specific 3D shape that allows proteins
to do their jobs

6. -but proteins fold in on themselves…
….to make a specific 3D shape that allows proteins
to do their jobs
**REMEMBER**
Amino Acid  Protein  Protein’s
order shape Function
Or simply
Order  Shape  Function

8. Proteins: the hardest working molecule
Possible Protein Functions:
Structural support (helps keep cell’s shape)
Storage
Transport across cell membrane
Sensory reception (communication between cells)
Contractions (movement)
Defense (t-cells, red blood cells)
Gene Regulation
Building bone, brain, muscle, organ cells
Transporting Oxygen in blood
ENZYMES***

9. Enzymes
Pg 52
Act as CATALYSTS that can speed up some reactions by more than a billion times!
Enzymes work by a physical fit (Lock and Key) between the enzyme molecule and its SUBSTRATE, the reactant being catalyzed.
Enzymes reduces the activation energy for the chemical reaction to occur.
After the reaction, the enzyme is released and is unchanged, so it can be used many times
Enzyme names end in –”ase”

10. Enzyme & Substrate fit like a lock & key (Shape specific)
Pg 52
pH or temperature can change the active site shape on any enzyme
Active site is where the reactants bind to the enzyme

11. 3 genes on one DNA strand coding for 3 separate proteins
Gene:a specific segment of DNA that codes
for a protein
Ex:
Gene 1
Gene 2
Gene 3
3 genes on one DNA strand coding for 3 separate proteins

12. Gene 1
Gene 2
Gene 2
Transcription: Copying one side of DNA and creating a strand of mRNA . This happens inside the nucleus all the time
-when completed, the mRNA that was transcribed from a specific gene will then travel outside the nucleus to be Translated

13. mRNA can bind to single DNA strand
DNA Codon
Transcribed Strand 
A T G G A T A C A A T
T A C C T A T G T T A
Un-Transcribed
Side
mRNA
U A C C U A U G U U A
mRNA Codon

14. Gene 1 Gene 2 Gene 3 Gene Transcription to mRNA
In Eukaryotes the mRNA is “processed” before it leaves the nucleus
Introns (Junk RNA) are removed
Exons (working RNA) are spliced together to make a full mRNA chain that then will leave the nucleus

15. Exon 1
Exon 2
Exon 3
Exon 1
Exon 2
Exon 3

18. Transcription Animations:
Translation Animations:

19. COPY THE NEXT DIAGRAM Translation: using mRNA (from transcription)
After mRNA leaves the nucleus:
Translation: using mRNA (from transcription)
to create a chain of Amino Acids (a.k.a. Proteins)
-the process requires: mRNA
tRNA
Ribosomes
COPY THE NEXT DIAGRAM
Remember cells use proteins for all kinds of different jobs:
-Transportation across membrane, digestion, building organelles & other cell structures, and of course..ENZYMES

20. COPY DIAGRAM with labels

21. The genetic code reads for the mRNA codon, NOT the tRNA Anticodon
Pg 303
The genetic code reads for the mRNA codon,
NOT the tRNA Anticodon

22. A G T U C A U C A A G U DNA: Translation TRANSCRIBED SIDE
Transcription
A G T
U C A
mRNA
Codon
U C A
mRNA
Codon
Translation
tRNA
AntiCodon
A G U
Serine
Amino Acid

23. T A C C T A T G T T A A T G G A T A C A A T U A C C U A U G U U A
Ex Problem:
DNA Codon
DNA
Un-transcribed Strand 
T A C C T A T G T T A
A T G G A T A C A A T
Transcribed Side
mRNA
Codon
mRNA
U A C C U A U G U U A
tRNA
AntiCodon
Amino Acids
A U G
Tyrosine
G A U
Leucine
A C A
Cysteine

24. The genetic code reads for the mRNA codon,
NOT the tRNA Anticodon

25. Transcription & Translation